通過ViewModel實現(xiàn)的數(shù)據(jù)共享符合Android的MVC設(shè)計模式，將數(shù)據(jù)獨立出來
成都創(chuàng)新互聯(lián)主要從事成都網(wǎng)站建設(shè)、網(wǎng)站建設(shè)、網(wǎng)頁設(shè)計、企業(yè)做網(wǎng)站、公司建網(wǎng)站等業(yè)務(wù)。立足成都服務(wù)湯旺,10余年網(wǎng)站建設(shè)經(jīng)驗,價格優(yōu)惠、服務(wù)專業(yè),歡迎來電咨詢建站服務(wù):18980820575
實現(xiàn)的Demo
1、主頁面通過SeekBar 來改變數(shù)字的值
2、點擊進入就進入第二個界面，但是數(shù)據(jù)還是共享的
3、隨便加兩個數(shù)字上去，再次切換
4、發(fā)現(xiàn)數(shù)據(jù)還是共享的
下面是具體實現(xiàn)步驟：
1、建立兩個Fragment（使用了Binding 和 Navigation）
一點要添加Binding 和 Navigation 不然做不了
2、建立一個繼承于ViewModel的類
3、分別在兩個Fragment的代碼中使用繼承于ViewModel的那個類，就可以實現(xiàn)數(shù)據(jù)共享
下面是具體代碼：
1、繼承于ViewModel的類
重慶分公司
重慶分公司
package com.example.naviation01;
import androidx.lifecycle.MutableLiveData;
import androidx.lifecycle.ViewModel;
public class MyViewMode extends ViewModel {
private MutableLiveData number;
public MutableLiveData getNumber(){
if(this.number == null){
this.number = new MutableLiveData<>();
this.number.setValue(0);
}
return this.number;
}
public void add(int x){
this.number.setValue(this.number.getValue()+x);
if(this.number.getValue() < 0){
this.number.setValue(0);
}
}
}
2、Fragment 主頁
package com.example.naviation01;
import android.os.Bundle;
import androidx.databinding.DataBindingUtil;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentController;
import androidx.lifecycle.ViewModel;
import androidx.lifecycle.ViewModelProvider;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SeekBar;
import com.example.naviation01.databinding.FragmentHomeBinding;
/**
* A simple {@link Fragment} subclass.
*/
public class HomeFragment extends Fragment {
public HomeFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
final MyViewMode myViewMode;
myViewMode = ViewModelProviders.of(getActivity()).get(MyViewMode.class);
FragmentHomeBinding binding;
binding = DataBindingUtil.inflate(inflater,R.layout.fragment_home,container,false);
binding.setData(myViewMode);
binding.setLifecycleOwner(getActivity());
binding.seekBar.setProgress(myViewMode.getNumber().getValue());
binding.seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
myViewMode.getNumber().setValue(progress);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
binding.button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
NavController controller = Navigation.findNavController(v);
controller.navigate(R.id.action_homeFragment_to_detailFragment);
}
});
return binding.getRoot();
//return inflater.inflate(R.layout.fragment_home, container, false);
}
}
xml
<?xml version="1.0" encoding="utf-8"?>
3、Fragment 副頁
package com.example.naviation01;
import android.os.Bundle;
import androidx.databinding.DataBindingUtil;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProviders;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.naviation01.databinding.FragmentDetailBinding;
/**
* A simple {@link Fragment} subclass.
*/
public class DetailFragment extends Fragment {
public DetailFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
MyViewMode myViewMode;
myViewMode = ViewModelProviders.of(getActivity()).get(MyViewMode.class);
FragmentDetailBinding binding;
binding = DataBindingUtil.inflate(inflater,R.layout.fragment_detail,container,false);
binding.setDate(myViewMode);
binding.setLifecycleOwner(getActivity());
binding.button4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
NavController controller = Navigation.findNavController(v);
controller.navigate(R.id.action_detailFragment_to_homeFragment);
}
});
return binding.getRoot();
//return inflater.inflate(R.layout.fragment_detail, container, false);
}
}
xml
<?xml version="1.0" encoding="utf-8"?>
4、xml Main_Activity
<?xml version="1.0" encoding="utf-8"?>
總結(jié)
以上所述是小編給大家介紹的Android通過ViewModel保存數(shù)據(jù)實現(xiàn)多頁面的數(shù)據(jù)共享功能，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復(fù)大家的。在此也非常感謝大家對創(chuàng)新互聯(lián)網(wǎng)站的支持！
如果你覺得本文對你有幫助，歡迎轉(zhuǎn)載，煩請注明出處，謝謝！
